The present invention relates to a fuel supply system for supplying liquid fuel into a fuel tank, and more particularly relates to a barrier member, which is located within a fuel supply tube which conducts fuel to a fuel tank, and which prevents splashing back of fuel during filling of the fuel tank.
In an automotive vehicle or the like, for filling the fuel tank thereof, there is generally provided a fuel supply tube, a lower end of which is connected to the fuel tank, and an upper end of which is adapted for receiving a fuel nozzle of a fuel supply system such as a gasoline pump, said nozzle being inserted thereinto. It is very common for such a fuel supply tube to be bent or curved near its upper end, in order to conform it to the construction of the automobile body and the position of the fuel tank therein.
A problem occurs with such a fuel supply tube, which is particularly serious in the case of a curved fuel supply tube as described above. When fuel is being supplied into the fuel supply tube from a nozzle of a fuel pump or the like, it often occurs that the incoming fuel strikes the internal wall of the tube, especially on the radially outer side of any such curved portion, and a portion of this fuel may splash or bounce back up the fuel supply tube, so as to hit the fuel nozzle.
This can cause difficulties for two possible reasons. First, if the fuel splashes back sufficiently forcefully, it may even be ejected from out of the orifice of the fuel supply tube to spill down the body of the automobile, which is dirty and dangerous. Second, even if fuel does not actually splash back out of the fuel supply tube, there is a danger that splashed back fuel may trigger a fuel detector mounted on the fuel nozzle of the fuel supply pump. Generally, the nozzle of a fuel supply pump usually incorporates a fuel detector at or near its tip, which includes an auto-stop mechanism, in order to ensure that when the fuel tank of the vehicle has been completely filled by the fuel supplied from the nozzle, the fuel supply from the fuel pump is automatically cut off, when the level of fuel rises to above the tip of the nozzle. Thereby over filling of the fuel tank beyond the orifice of the fuel supply tube, which could cause spillage of large quantities of fuel, is positively prevented. However, splashing back of fuel may cause such an auto-stop mechanism to be triggered prematurely, and thus, before the fuel tank is properly filled, the supply of fuel by the fuel nozzle may be repeatedly interrupted, thus causing considerable inconvenience during filling of the tank. In the worst case, the time required for proper filling of the tank can be so long that the operation becomes impracticable.